Method for leveling tow

ABSTRACT

A device is provided acting upon a multifilament continuous filament tow band to improve the levelness of the tow band prior to further processing by intermittently transversely displacing some, but not all of the filaments of said tow at different locations across the tow band and allowing a sufficient tow path line of travel to allow the filaments to achieve new equilibrium locations with respect to each other.

United States Patent [1 1 Lohrke [54] METHOD FOR LEVELING TOW [75] Inventor: James L. Lohrke, Birmingham Township, Chester County, Pa.

[73] Assignee: Turbo Machine Company, Lansdale,

[22] Filed: Aug. 10, 1970 [2]] Appl. No.: 62,393

[52] U.S. Cl. ..19/65 T [51] lnt. Cl. ..D01d 11/02 [58] Field of Search"; ..19/65 T, 66 T [56] References Cited UNITED STATES PATENTS 2,822,582 2/1958 Hayward et al. ..19/65 T 3,254,373

6/1966 Pannill, Jr. et al. ..l9/65 T 1 Jan. 9, 1973 3,340,576 9/1967 Pannill, Jr. 6! al. ..19/65 r FOREIGN PATENTS OR APPLICATIONS 717,367 10/1966 Primary Examiner-Dorsey Newton Attorney-Paul & Paul [57] ABSTRACT A device is provided acting upon a multifilament continuous filament tow band to improve the levelness of the tow band prior to further processing by intermittently transversely displacing some, but not all of the filaments of said tow at different locations across the tow band and allowing a sufficient tow path line of travel to allow the filaments to achieve new equilibrium locations with respect to each other.

1 Claim, 4 Drawing Figures Italy ..19/65 T INVENTOR.

James L. Lohrke ATTORNEYS PATENTEDJAN 9 I973 SHEET 2 BF 2 INVENTOR. James L. Lohrke BY ATTORNEYS.

METHOD FOR LEVELING TOW BACKGROUND OF THE INVENTION This invention relates to an apparatus and method for handling a textile material such as filamentary tow, and more particularly, for distributing the filaments in continuous filament tow uniformly in a transverse section of the tow band, hereinafter referred to as leveling."

In the prior art many apparatus and methods are known for processing tow, including those which deal with crimping tow and cutting or breaking the tow into staple length fibers. In many of the known types of apparatus it is necessary to withdraw the tow from a carton and guide it usually through a plurality of bars to the input of apparatus for further processing. This invention is concerned with said guiding portion of the apparatus known as the creel rather than the processing portion. It is an object of this invention to condition the tow so that it is as uniform in cross-section as possible when it is fed to the apparatus for processing.

It is common to have folds in the filamentary tow sheet, particularly along the edges. Also, the tow may be more dense along the edges then it is in the center. The tow is comprised of a plurality of continuous synthetic filaments normally crimped and the crimps are normally in registration. A number of devices have been provided by the prior art for de-registering crimp and this invention is not concerned with such de-registration; nor is this device concerned with blooming of the tow sheet. Rather, it is concerned with achieving improved uniformity of levelness of the transverse cross section of the tow band.

Other devices have been provided for deflecting a tow while subjecting the filaments of the tow to a tension or draft ratio sufficient to cause the tow filaments to break into staple length fibers in sliver 'form. This invention does not convert tow into sliver, but is concerned with improving the levelness of the tow band.

SUMMARY OF THE INVENTION In the preferred embodiment of this invention, a beater is provided in the tow creel mounted for rotation in a direction opposite the direction of the travel of the tow band. The beater has a plurality of preferably cylindrical rods thereon axially positioned transverse to the path of travel of the tow band. These rods have grooves extending partially about their circumference, said grooves being preferably uniform V-grooves. The crests of the grooves from one rod to the next rod of the beater are axially out of phase with each other. The tow is maintained under some tension by means of running it through a plurality of bars. It is most preferable to have a tension bar on either side of the beater in close proximity therewith as will be explained hereinafter.

As the tow is drawn through this apparatus, the beater is rotated so that the grooved rods are brought into contact with the tow band and the crests penetrate the tow band thereby dividing it into a number of bundles of filaments. As each successive rod is brought into contact with the tow band, the crests make new, distinct penetrations in the tow band due to the axial displacement of the crests from one rod to the next, thereby dividing the tow band into new bundles of filaments. With each penetration into the tow band, some,

but not all, of the filaments on the tow band are displaced transversely. The ultimate effect of the numerous cycles of transverse displacement of the filaments as the tow is divided into numerous bundles of filaments, is to produce a more uniform density across the width of the tow band thereby improving levelness.

Accordingly, it is an object to provide a new apparatus and method for handling tow by which a tow band of more uniform cross-sectional density is produced.

This and other objects of the invention will become apparent from the following description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus in accordance with the preferred embodiment of this invention;

FIG. 2 is a plan view partially broken away of a portion of the apparatus shown in FIG. 1 with the tow band removed;

FIG. 3 is a section taken as indicated by the lines and arrows 3-3 in FIG. 2'with the tow band inserted and with a portion of the apparatus of FIG. 1 shown in' phantom, and with alternate positions of the tow band and apparatus of FIG. 2 shown in phantom; and

FIG. 4 is an enlarged view of that portion of the apparatus designated 4 in FIG. 2 illustrating diagramatically the phase relation between the successive grooves in that portion of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Although specific forms of the invention have been selected for illustration in the drawings, and the following description is drawn in specific terms for the purpose of describing these forms of the invention, this description is not intended to limit the scope of the invention which is defined in the appended claims.

Referring to the figures, FIG. 1 shows a portion of a frame of a creel designated generally 10 of an apparatus used for guiding a tow band from a carton (not shown) to a machine (not shown) for processing. The frame includes a plurality of guide bars 12, 14, 16, 18, 20 and 22 which are fixedly mounted thereto for guiding the tow 24 as it comes from the carton and as it is delivered downstream. The tow 24 is composed of a plurality of continuous filament synthetic strands which may or may not be crimped. The strands lie in a band or sheet which is drawn out rather flat like a tape as it is passed over and under the guide bars. Further, the guide bars have the effect of tensioning the tow band as it advances in the direction of the arrows.

Mounted in the path of this advancing tow 24 are a plurality of heaters 26 and 28, each mounted for rotation in response to any convenient mode of power transmission means on centrally located shafts 31, 29 respectively, disposed in bearings as at 30, 32 and 34, 36 respectively, mounted on the frame 10. A power transmission means is illustrated by the motor 38 which has an output drive shaft 39 having mounted thereon a pulley 40 with a belt 41 transmitting power to a pulley 42 on the end of the shaft 29 for rotating the shaft in the direction of the arrow. Also mounted on the shaft 29 is a pulley 43 which has disposed about it a belt 44 which is also disposed about a pulley 45 on the end of the shaft 31, so that as the pulley 43 rotates with the shaft 29, the pulley 45 rotates in the direction of the arrow thereon and drives the shaft 31. The beaters 26 and 28 are thus driven in the direction of the arrows thereon, opposite to the direction of travel of the tow band 24 as indicated by the arrows thereon.

In FIG. 1 a plurality of beaters are shown since this represents the most preferred embodiment of this invention. However it will be understood that the invention can be practiced with a single beater or even more than two beaters. I will now describe in detail one of the beaters shown, since the heaters are similarly constructed.

The beater 26 is shown in greater detail in FIG. 2 and consists of a pair of end plates or discs 50 and 52 fixed on the axial shaft 31 by means of hubs 54 and 56 respectively for rotation therewith. Fixedly mounted between the end plates are a plurality of preferably cylindrical bodies or rods, each of which has a grooved surface. The grooves are preferably uniform at least partially circumferential V-grooves as 62, 63. The V- grooves are spaced along substantially the entire length of the rods 58, 59 and 60. Both the crests and roots of the grooves are preferably sharp and the grooves are continuous, smooth arcuate surfaces in the circumferential direction.

The rods are arranged so that the grooves are transversely out of phase as more clearly shown in the enlargement of FIG. 4. The grooves on rod 58 are not aligned with the grooves on rod 59 and the grooves on both of these rods are not aligned with the grooves on rod 60. Thus, while the grooves on all the rods are the same size, their crests and roots are axially out of phase with one another from rod to rod transversely of the direction of movement of the tow. For example, the crest 65 on rod 58 in FIG. 4 is misaligned with the crest 67 on rod 59 so that line A drawn through the crest 65 passes to the left of the crest 67. The crest 71 on rod 60 is also misaligned or out of phase with respect to the crest 65 as can be seen by the line A passing through the crest 65 and to the right of the crest 71. Likewise, crest 71 is out of line with the crest 67.

There are preferably three such rods on each beater and there are most preferably two heaters in the creel, one spaced downstream from the other longitudinally. As the tow is drawn through the creel the beaters are rotated and the rods engage the tow band 24 in the manner shown in FIG. 3. Therein the rod 59 has engaged one transverse surface of the tow band and has diverted it from its normal vertical course between the guide bars 14 and 16. To a certain extent then it has tensioned the tow.

As shown the crest 73 of the rod 59 passed through the tow sheet with the effect that it is divided into a plurality of filamentary bundles. Since the guide bars 14 and 16 are in close proximity with the beater 26, the bundles are spread to the greatest degree as they pass over rod 59 and tend to come together at both the bar 14 and the bar 16. As the beater 26 continues to rotate the rod 59 moves to the position shown in phantom in FIG. 3 and a second rod 60 engages the tow band. It must be remembered that the tow band is moving during this time, so that the filament bundles are to some extent traversing and changing position on the bar l6.

However, they are maintained under some degree of tension so that they do preserve to an extent their integrity. As the tow moves in one direction and the beater rods move in the other, there will be some.over-' riding of the crests of the rods by the filaments of the tow band with the result that there is some exchange of filaments between separately defined bundles and improved levelness.

The crests of the rod 60 will engage the tow bundles and redivide them. This results from the out of phase relation of the grooves on successive rods and is madeeven more positive by the close proximity of the bar 16 to the beater 26 which tends to maintain the transverse tow band width.

By adjusting the speed of the beater 26 it is possible to engage the same portion of the tow band with all three rods 58, 59 and 60 and it is even possible to engage the same portion of the tow twice with all three rods, so that a given portion of tow bandwill be engaged by the grooves and sub-divided as much as six times in'passing between the bars 14 and 16.

The V-shaped smooth arcuate grooves provide for particularly smooth entry and withdrawal of the crests in separating the tow into bundles, so that snags are avoided.

As previously stated it is most desirable to have two such beaters in this creel. It has been found that folds which build up along an edge .of the tow band and are folded over on either of the two sides of the tow band are more responsive to being unfolded by the action rods acting on both sides of the band. Thus, it has been found that stubborn folds which resist unfolding by a single set of rods acting on one side of the tow band, can be unfolded by the second set of rods acting on the other side of the tow band.

It will be understood that various changes in the details, materials and arrangement of parts which have been herein described and illustrated in order to explain the nature of this invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

For example, while it is usual for the beater to rotate so that its action on the tow band is in the opposite direction to the movement of the tow, in certain tows improved levelness may result from rotating the beater in the same direction as the tow is traveling.

Also, it is within the scope of this invention to adjust the position of the bars 14 and 16 FIG. 3 with respect to the axis of the shaft 31 so as to regulate the amount of contact which the grooved rods have with the surface of the tow band. In fact it is conceivable that there may be intermittent periods when no rod is in contact with the tow band, as when the bars 14 and 16 are moved far enough to the right when viewed as inFIG. 3 with respect to the beater 26.

While a rotating beater with grooved rods has been described as the preferred embodiment of the invention, othermeans can be used to achieve the separation and lateral redistribution of the filiments in the tow band. One such means is a number of air jets located transversly across the tow band regulated in such a manner to perform the same function as the crests of the rods.

As another alternate embodiment a flat blade (or blades) with V-shaped sharp toothed serrations could be used to penetrate the tow band at differing transverse locations to create the same effect.

What is claimed is:

1. The process of improving the levelness of the cross-sectional density of a continuously moving band of filamentary tow, comprising the steps of:

a. advancing the tow under tension of an amount in-- sufficient to cause substantial filament breakage in a plane between two fixed bars; and

b. intermittently laterally separating the tow band into filamentary bundles and allowing the bundles to reform into a band, by:

initially engaging one face of the tow band between the bars to deflect it from its path of travel in said plane to differentially laterally separate some of the filaments with respect to others in the tow band while simultaneously differentially longitudinally increasing the tension in those filaments;

. and then decreasing the tension in the filaments which have had their tension increased-while continuing to engage the tow band;

. and then engaging the same face of the tow band and then removing the initial engagement from the face of said tow to allow lateral movement of the filaments, previously separated by said initial continuing engagement, toward the filaments from which they had been separated, while simultaneously maintaining the second engagement with the face of said tow;

. and then repeating the above steps (2), (3) and (4) so that initial and subsequent engagement occurs intermittently. 

1. The process of improving the levelness of the cross-sectional density of a continuously moving band of filamentary tow, comprising the steps of: a. advancing the tow under tension of an amount insufficient to cause substantial filament breakage in a plane between two fixed bars; and b. intermittently laterally separating the tow band into filamentary bundles and allowing the bundles to reform into a band, by:
 1. initially engaging one face of the tow band between the bars to deflect it from its path of travel in said plane to differentially laterally separate some of the filaments with respect to others in the tow band while simultaneously differentially longitudinally increasing the tension in those filaments;
 2. and then decreasing the tension in the filaments which have had their tension increased while continuing to engage the tow band;
 3. and then engaging the same face of the tow band again to deflect it from its plane of travel at a point between the point of continuing engagement and one of said bars to differentially laterally separate the filaments in the tow band at different locations, again increasing the tension in said filaments an amount insufficient to cause substantial filament breakage;
 4. and then removing the initial engagement from the face of said tow to allow lateral movement of the filaments, previously separated by said initial continuing engagement, toward the filaments from which they had been separated, while simultaneously maintaining the second engagement with the face of said tow;
 5. and then repeating the above steps (2), (3) and (4) so that initial and subsequent engagement occurs intermittently.
 2. and then decreasing the tension in the filaments which have had their tension increased while continuing to engage the tow band;
 3. and then engaging the same face of the tow band again to deflect it from its plane of travel at a point between the point of continuing engagement and one of said bars to differentially laterally separate the filaments in the tow band at different locations, again increasing the tension in said filaments an amount insufficient to cause substantial filament breakage;
 4. and then removing the initial engagement from the face of said tow to allow lateral movement of the filaments, previously separated by said initial continuing engagement, toward the filaments from which they had been separated, while simultaneously maintaining the second engagement with the face of said tow;
 5. and then repeating the above steps (2), (3) and (4) so that initial and subsequent engagement occurs intermittently. 